The Evolution of the Eye
The evolution of the eye has been progressing perhaps 2 billion years. (It evolved separately 42 times). Assume your average animal generation is 2 years, how many generations is that? 1 billion. Do realise how little has to change in each generation? just 1 billionth of the job. Evolution is incredibly slow and stupid — IQ (Intelligence Quotient) 1. It has no ability to plan or design. It works entirely by trial and error. The only reason it works at all is because it is so patient and relentless.
The key to understanding is that even the most primitive eye (a set of light sensitive cells) is better than no eye. The evolutionary chain is a series of continuous improvements each a tad better than the last. There are animals living today at all these intermediate stages.~ Roedy (1948-02-04 age:70)